Influence of T cation on the vibrational properties of ferroelectric Ca2TO4 (T = Si, Ti, Mn, Ge) compounds

IF 3.8 Q2 CHEMISTRY, PHYSICAL

Chemical Physics Impact Pub Date : 2024-12-21 DOI:10.1016/j.chphi.2024.100804

Neenu Saini , Ruby Jindal , Archana Tripathi , Harleen Kaur , Raminder Kaur

{"title":"Influence of T cation on the vibrational properties of ferroelectric Ca2TO4 (T = Si, Ti, Mn, Ge) compounds","authors":"Neenu Saini , Ruby Jindal , Archana Tripathi , Harleen Kaur , Raminder Kaur","doi":"10.1016/j.chphi.2024.100804","DOIUrl":null,"url":null,"abstract":"<div><div>The analysis of Raman and Infrared (IR) phonons in monolayered tetragonal Ca2TO4 (T = Si, Ti, Mn, Ge) compounds, which exhibit <math><msubsup><mi>D</mi><mrow><mn>17</mn></mrow><mrow><mn>4</mn><mi>h</mi></mrow></msubsup></math> symmetry and belong to the I4/mmm phase of space group 139 with Z = 2, has been conducted using normal coordinates. The Ca2TO4 (T = Si, Ti, Mn, Ge) compounds are the first members of the Ruddlesden-Popper (RP) series denoted as Can+1TO3n+1 (T = Si, Ti, Mn, Ge) with n = 1. Nine Short-Range Force Constants (SRFC) have been included in theoretical calculations to analyze the optical phonons of Ca2TO4 (T = Si, Ti, Mn, Ge) compounds within the I4/mmm phase. The assignments of optical vibrational modes in Ca2TO4 (T = Si, Ti, Mn, Ge) compounds have been determined using Wilson's GF-Matrix Method and cross-referenced with data obtained from similar structural characteristics. The analysis also involved studying how the exchange of cation-T (T = Si, Ti, Mn, Ge) impacts the lattice dynamics of the isostructural compounds Ca2TO4 (T = Si, Ti, Mn, Ge) in the context of monolayered tetragonal structures. In this analysis, a comparison has been made between the vibrational modes at the Zone Center, the force constants, and bond lengths to assess the influence of the cation exchange. The frequencies predominantly influenced by the T-atoms (T = Si, Ti, Mn, Ge) exhibit distinctive characteristics that vary with atomic number, underscoring the profound impact of T-atoms (T = Si, Ti, Mn, Ge) size on vibrational properties of Ca2TO4 (T = Si, Ti, Mn, Ge) compounds. The analysis of force constant variations between Ca2TO4 (T = Si, Ge) and Ca2TO4 (T = Ti, Mn) revealed differences attributed to the distinctive orbital setups of the T-atoms. Furthermore, for each normal mode in the Ruddlesden-Popper phase Ca2TO4 (T = Si, Ti, Mn, Ge), the examination of Potential Energy Distribution (PED) sheds light on the significant impact exerted by Short-Range Force Constants on the calculated vibrational modes, providing a deeper understanding of their behavior and interactions.</div></div>","PeriodicalId":9758,"journal":{"name":"Chemical Physics Impact","volume":"10 ","pages":"Article 100804"},"PeriodicalIF":3.8000,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Physics Impact","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2667022424003487","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}

引用次数: 0

Abstract

The analysis of Raman and Infrared (IR) phonons in monolayered tetragonal Ca₂TO₄ (T = Si, Ti, Mn, Ge) compounds, which exhibit

D_{17}^{4 h}

symmetry and belong to the I4/mmm phase of space group 139 with Z = 2, has been conducted using normal coordinates. The Ca₂TO₄ (T = Si, Ti, Mn, Ge) compounds are the first members of the Ruddlesden-Popper (RP) series denoted as Ca_n+1TO_3n+1 (T = Si, Ti, Mn, Ge) with n = 1. Nine Short-Range Force Constants (SRFC) have been included in theoretical calculations to analyze the optical phonons of Ca₂TO₄ (T = Si, Ti, Mn, Ge) compounds within the I4/mmm phase. The assignments of optical vibrational modes in Ca₂TO₄ (T = Si, Ti, Mn, Ge) compounds have been determined using Wilson's GF-Matrix Method and cross-referenced with data obtained from similar structural characteristics. The analysis also involved studying how the exchange of cation-T (T = Si, Ti, Mn, Ge) impacts the lattice dynamics of the isostructural compounds Ca₂TO₄ (T = Si, Ti, Mn, Ge) in the context of monolayered tetragonal structures. In this analysis, a comparison has been made between the vibrational modes at the Zone Center, the force constants, and bond lengths to assess the influence of the cation exchange. The frequencies predominantly influenced by the T-atoms (T = Si, Ti, Mn, Ge) exhibit distinctive characteristics that vary with atomic number, underscoring the profound impact of T-atoms (T = Si, Ti, Mn, Ge) size on vibrational properties of Ca₂TO₄ (T = Si, Ti, Mn, Ge) compounds. The analysis of force constant variations between Ca₂TO₄ (T = Si, Ge) and Ca₂TO₄ (T = Ti, Mn) revealed differences attributed to the distinctive orbital setups of the T-atoms. Furthermore, for each normal mode in the Ruddlesden-Popper phase Ca₂TO₄ (T = Si, Ti, Mn, Ge), the examination of Potential Energy Distribution (PED) sheds light on the significant impact exerted by Short-Range Force Constants on the calculated vibrational modes, providing a deeper understanding of their behavior and interactions.

Abstract Image